<!-- 比较完美 移动端首选
不兼容 ie9 及以下 -->
<!DOCTYPE html>
<html>
  <head>
    <title>flex</title>
    <meta charset="UTF-8" />
    <style>
      html * {
        margin: 0;
        padding: 0;
      }

      .left,
      .right {
        width: 100px;
      }

      .left {
        background-color: red;
      }

      .right {
        background-color: blue;
      }

      .center {
        background-color: yellow;
      }

      .container {
        display: flex;
      }

      .center {
        flex: 1;
      }
    </style>
  </head>

  <body>
    <div class="container">
      <div class="left">我是left</div>
      <div class="center">
        <h2>我是center,通过flex实现</h2>
        flex:
      </div>
      <div class="right">我是right</div>
    </div>
    <div>333333333333333333</div>
  </body>
</html>
